.. _http-client-sample:

HTTP Client
###########

Overview
********

This sample application shows how to create HTTP 1.1 requests to
an HTTP server and how to parse the incoming responses.
Supported HTTP 1.1 methods are: GET, HEAD and POST.

The source code for this sample application can be found at:
:file:`samples/net/http_client`.

Requirements
************

- :ref:`networking_with_qemu`
- Terminal emulator software
- HTTP Server
- DNS server (optional)


Building and Running
********************

Open the project configuration file for your platform, for example:
:file:`prj_qemu_x86.conf` is the configuration file for QEMU.

To use QEMU for testing, follow the :ref:`networking_with_qemu` guide.

For IPv4 networks, set the following variables:

.. code-block:: console

	CONFIG_NET_IPV4=y
	CONFIG_NET_IPV6=n

IPv6 is the preferred routing technology for this sample application,
if CONFIG_NET_IPV6=y is set, the value of CONFIG_NET_IPV4=y is ignored.

In this sample application, both static IP addresses and DHCPv4 are supported.
Static IP addresses are specified in the project configuration file,
for example:

.. code-block:: console

	CONFIG_NET_APP_MY_IPV6_ADDR="2001:db8::1"
	CONFIG_NET_APP_PEER_IPV6_ADDR="2001:db8::2"

are the IPv6 addresses for the HTTP client running Zephyr and the
HTTP server, respectively. The application also supports DNS resolving so the
peer address is resolved automatically if host name is given, so you
can also write the HTTP server name like this:

.. code-block:: console

	CONFIG_NET_APP_MY_IPV6_ADDR="2001:db8::1"
	CONFIG_NET_APP_PEER_IPV6_ADDR="6.zephyr.test"

Open the :file:`src/config.h` file and set the server port
to match the HTTP server setup, for example:

.. code-block:: c

   #define SERVER_PORT		8000

assumes that the HTTP server is listening at the TCP port 8000.

HTTP Server
===========

Sample code for a very simple HTTP server can be downloaded from the
zephyrproject-rtos/net-tools project area:
https://github.com/zephyrproject-rtos/net-tools

Open a terminal window and type:

.. code-block:: console

   $ cd net-tools
   $ ./http-server.sh


DNS setup
=========

The net-tools project provides a simple DNS resolver. You can activate
it like this if you want to test the DNS resolving with HTTP client.

Open a terminal window and type:

.. code-block:: console

    $ cd net-tools
    $ ./dnsmasq.sh


Sample Output
=============

This sample application loops a specified number of times doing several
HTTP 1.1 requests and printing some output. The requests are:

- GET "/index.html"
- HEAD "/"
- POST "/post_test.php"
- GET "/big-file.html"

The terminal window where QEMU is running will show something similar
to the following:

.. code-block:: console

   [http-client] [INF] do_sync_http_req: [19] Send /index.html
   [http-client] [INF] do_sync_http_req: HTTP server response status: OK
   [http-client] [INF] do_sync_http_req: HTTP body: 170 bytes, expected: 170 bytes
   [http-client] [INF] do_sync_http_req: [19] Send /
   [http-client] [INF] do_sync_http_req: HTTP server response status: OK
   [http-client] [INF] do_sync_http_req: [19] Send /post_test.php
   [http-client] [INF] do_sync_http_req: HTTP server response status: OK
   [http-client] [INF] do_sync_http_req: HTTP body: 24 bytes, expected: 24 bytes
   [http-client] [INF] do_sync_http_req: [20] Send /index.html
   [http-client] [INF] do_sync_http_req: HTTP server response status: OK
   [http-client] [INF] do_sync_http_req: HTTP body: 170 bytes, expected: 170 bytes
   [http-client] [INF] do_sync_http_req: [20] Send /
   [http-client] [INF] do_sync_http_req: HTTP server response status: OK
   [http-client] [INF] do_sync_http_req: [20] Send /post_test.php
   [http-client] [INF] do_sync_http_req: HTTP server response status: OK
   [http-client] [INF] do_sync_http_req: HTTP body: 24 bytes, expected: 24 bytes
   [http-client] [INF] main: --------Sending 20 async request--------
   [http-client] [INF] do_async_http_req: [1] Send /index.html
   [http-client] [INF] response: Received 356 bytes piece of data
   [http-client] [INF] response: HTTP server response status: OK
   [http-client] [INF] response: HTTP body: 170 bytes, expected: 170 bytes
   [http-client] [INF] do_async_http_req: [1] Send /
   [http-client] [INF] response: HTTP server response status: OK
   [http-client] [INF] do_async_http_req: [1] Send /post_test.php
   [http-client] [INF] response: Received 163 bytes piece of data
   [http-client] [INF] response: HTTP server response status: OK
   [http-client] [INF] response: HTTP body: 24 bytes, expected: 24 bytes
   [http-client] [INF] do_async_http_req: [1] Send /big-file.html
   [http-client] [INF] response: Received 657 bytes piece of data
   [http-client] [INF] response: Received 640 bytes piece of data
   [http-client] [INF] response: Received 418 bytes piece of data
   [http-client] [INF] response: HTTP server response status: OK
   [http-client] [INF] response: HTTP body: 1528 bytes, expected: 1528 bytes